The objective of the study is to house and manage a breeding colony of 117 chimpanzees that will serve as a national resource of animals for biomedical and behavioral research. The specific aims are: Aim 1. To maintain a colony of chimpanzees composed of proven breeders and potential breeders for perpetuation of the colony. Aim 2. To continue the use of the harem breeding system which will provide about 25 pregnancies per year. Aim 3. To maintain the research resource as a stable, self-perpetuating colony by providing excellent animal husbandry, veterinary care, and a new housing facility. Aim 4. To develop an accurate and thorough computer system that will provide high quality long term records of animal health, pedigree, behavior, and research uses. Aim 5. To create a new behavioral biology division that will develop an applied and basic behavioral research program which will support the long-term research goals of the Chimpanzee Breeding and Research Program. The proposed colony has 77 confirmed breeders and 40 potential breeders. A harem system (1 male + 3 females) of breeding will be used to provide genetic diversity, protection against widespread disease transmission, and excellent reproduction. Approximately 50% of the chimpanzees produced will be retained each year to serve as eventual replacement breeders. The ratio will be four females to one male. Infants destined for breeding will be left with their mothers for one year. After weaning, they will be housed in peer groups in large indoor/outdoor housing. A new $10.5 million will be built during the new grant period. The entire National Chimpanzee Breeding Research Program animals will be housed in indoor/outdoor quarters with access to exercise yards. A computer network system that will enable the facility to establish a centralized up to date data base will established for the first time. Behavioral management and studies of the chimpanzee colony will enable PRL to provide programs for psychological enrichment, breeding, sociosexual development, and modifying behaviors of animals in need of rehabilitation following use in biomedical research after their return to PRL. Initially, of significant importance will be the studying of chimpanzees' behavior for group/harem allocation into the new facility.